Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Trop Anim Health Prod ; 52(4): 2179-2189, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32128662

RESUMO

Cattle production is an essential livelihood strategy in south-western Burkina Faso. Although having a distinct cultural role and known to be resistant against African animal trypanosomosis, the Lobi taurine cattle breed is endangered due to its low market value. As the first step in preservation efforts, our study aimed to develop a typology of production systems at the farm level. We used a structured questionnaire and focus group discussions for collecting data on household characteristics, socioeconomic activities, livestock, and access to services. The sample comprised 169 households in three communities. The analytical strategy included factor analysis of mixed data and hierarchical clustering. We identified four distinct types of cattle production systems: (1) sedentary Lobi farms, (2) sedentary crossbreed farms, (3) semi-transhumant Fulani zebu farms, and (4) transhumant Fulani zebu farms. Significant factors in developing this typology were the farmers' ethnic group, crop diversity, cattle herd size, cattle herd composition, number of small ruminants, and livestock management strategies. Across all production systems, men were considered being primary decision-makers in cattle production, with women, herders, and children being responsible for specific tasks. All identified production systems are increasingly confronting disease pressure and scarcity of water and land. Future efforts in preservation and breeding will need to respond to these trends in the agroecosystem, integrate risk management measures, and resonate with the specific needs of the different household members involved in cattle rearing.


Assuntos
Criação de Animais Domésticos , Cruzamento , Fazendeiros , Gado , Animais , Burkina Faso , Bovinos , Características da Família , Fazendas , Feminino , Grupos Focais , Humanos , Masculino , Inquéritos e Questionários
2.
Dev Comp Immunol ; 106: 103614, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31962062

RESUMO

The emergent availability in public databases of more complete genome assemblies allows us to improve genomic data obtained by classical molecular cloning. The main goal of this study was to refine the genomic map of the dromedary TRG locus by integrating our previous genomic data with the analysis of recent genomic assemblies. We identified an additional TRGC cassette, defined as a V-J-C recombination unit, located at the 5' of the locus and made up of five TRGV genes followed by three TRGJ genes and one TRGC gene. Hence, the complete dromedary TRG locus spans about 105 Kb and consists of three in tandem TRGC cassettes delimited by AMPH and STARD3NL genes at the 5' and 3' end, respectively. An expression assay carried out on peripheral blood showed the functional competency for the dromedary TRGC5 cassette and confirmed the presence of the somatic hypermutation mechanism able to enlarge the repertoire diversity of the dromedary γδ T cells.


Assuntos
Camelus/imunologia , Loci Gênicos/genética , Receptores de Antígenos de Linfócitos T gama-delta/genética , Linfócitos T/metabolismo , Animais , Evolução Molecular , Variação Genética , Genoma , Filogenia , Recombinação Genética , Alinhamento de Sequência , Ovinos , Hipermutação Somática de Imunoglobulina
3.
Anim Genet ; 50(6): 598-612, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31532019

RESUMO

Old World camels have served humans in cross-continental caravans, transporting people and goods, connecting different cultures and providing milk, meat, wool and draught since their domestication around 3000-6000 years ago. In a world of modern transport and fast connectivity, these beasts of burden seem to be out-dated. However, a growing demand for sustainable milk and meat production, especially in countries affected by climate change and increasing desertification, brings dromedaries (Camelus dromedarius) and Bactrian camels (Camelus bactrianus) back onstage and into the focus of animal breeders and scientists. In this review on the molecular genetics of these economically important species we give an overview about the evolutionary history, domestication and dispersal of Old World camels, whereas highlighting the need for conservation of wild two-humped camels (Camelus ferus) as an evolutionarily unique and highly endangered species. We provide cutting-edge information on the current molecular resources and on-going sequencing projects. We cannot emphasise enough the importance of balancing the need for improving camel production traits with maintaining the genetic diversity in two domestic species with specific physiological adaptation to a desert environment.


Assuntos
Camelus/genética , Migração Animal , Animais , Evolução Biológica , Camelus/anatomia & histologia , Camelus/classificação , Camelus/fisiologia , Domesticação , Hibridização Genética
4.
Anim Genet ; 45(4): 550-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24749721

RESUMO

The tradition of animal husbandry in the context of a nomadic lifestyle has been of great significance in the Mongolian society. Both Bactrian camels and horses have been invaluable for the survival and development of human activities in the harsh arid environment of the Mongolian steppe. As camels offer unique and sustainable opportunities for livestock production in marginal agro-ecological zones, we investigated the current genetic diversity of three local Mongolian camel breeds and compared their levels of variation with common native Mongolian camels distributed throughout the country. Based on mitochondrial and nuclear markers, we found levels of genetic diversity in Mongolian populations similar to that reported for Chinese Bactrian camels and for dromedaries. Little differentiation was detected between single breeds, except for a small group originating from the northwestern Mongolian Altai. We found neither high inbreeding levels in the different breeds nor evidence for a population decline. Although the Mongolian camel census size has severely declined over the past 20 years, our analyses suggest that there still exists a stable population with adequate genetic variation for continued sustainable utilization.


Assuntos
Camelus/genética , Variação Genética , Animais , Núcleo Celular/genética , DNA Mitocondrial/genética , Dados de Sequência Molecular , Mongólia , Reação em Cadeia da Polimerase/veterinária , Análise de Sequência de DNA/veterinária
5.
Mol Ecol ; 20(4): 706-24, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21214655

RESUMO

The cheetah (Acinonyx jubatus) has been described as a species with low levels of genetic variation. This has been suggested to be the consequence of a demographic bottleneck 10 000-12 000 years ago (ya) and also led to the assumption that only small genetic differences exist between the described subspecies. However, analysing mitochondrial DNA and microsatellites in cheetah samples from most of the historic range of the species we found relatively deep phylogeographic breaks between some of the investigated populations, and most of the methods assessed divergence time estimates predating the postulated bottleneck. Mitochondrial DNA monophyly and overall levels of genetic differentiation support the distinctiveness of Northern-East African cheetahs (Acinonyx jubatus soemmeringii). Moreover, combining archaeozoological and contemporary samples, we show that Asiatic cheetahs (Acinonyx jubatus venaticus) are unambiguously separated from African subspecies. Divergence time estimates from mitochondrial and nuclear data place the split between Asiatic and Southern African cheetahs (Acinonyx jubatus jubatus) at 32 000-67 000 ya using an average mammalian microsatellite mutation rate and at 4700-44 000 ya employing human microsatellite mutation rates. Cheetahs are vulnerable to extinction globally and critically endangered in their Asiatic range, where the last 70-110 individuals survive only in Iran. We demonstrate that these extant Iranian cheetahs are an autochthonous monophyletic population and the last representatives of the Asiatic subspecies A. j. venaticus. We advocate that conservation strategies should consider the uncovered independent evolutionary histories of Asiatic and African cheetahs, as well as among some African subspecies. This would facilitate the dual conservation priorities of maintaining locally adapted ecotypes and genetic diversity.


Assuntos
Acinonyx/genética , Genética Populacional , Filogeografia , África , Animais , Ásia , Núcleo Celular/genética , Conservação dos Recursos Naturais , DNA Mitocondrial/genética , Evolução Molecular , Variação Genética , Genótipo , Irã (Geográfico) , Repetições de Microssatélites , Análise de Sequência de DNA
6.
Mol Ecol Resour ; 10(6): 1106-8, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21565125

RESUMO

This article documents the addition of 205 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Bagassa guianensis, Bulweria bulwerii, Camelus bactrianus, Chaenogobius annularis, Creontiades dilutus, Diachasmimorpha tryoni, Dioscorea alata, Euhrychiopsis lecontei, Gmelina arborea, Haliotis discus hannai, Hirtella physophora, Melanaphis sacchari, Munida isos, Thaumastocoris peregrinus and Tuberolachnus salignus. These loci were cross-tested on the following species: Halobaena caerulea, Procellaria aequinoctialis, Oceanodroma monteiroi, Camelus ferus, Creontiades pacificus, Dioscorea rotundata, Dioscorea praehensilis, Dioscorea abyssinica, Dioscorea nummularia, Dioscorea transversa, Dioscorea esculenta, Dioscorea pentaphylla, Dioscorea trifida, Hirtella bicornis, Hirtella glandulosa, Licania alba, Licania canescens, Licania membranaceae, Couepia guianensis and 7 undescribed Thaumastocoris species.

7.
Anim Genet ; 41(3): 315-8, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19968638

RESUMO

Hybridization between wild species and their domestic congeners often threatens the gene pool of the wild species. The last wild Bactrian camel (Camelus ferus) populations in Mongolia and China are examples of populations facing such a hybridization threat. To address this key issue in the conservation of wild camels, we analysed wild, hybrid and domestic Bactrian camels (Camelus bactrianus) originating from Mongolia, China and Austria. Through screening of an 804-base-pair mitochondrial fragment, we identified eight mitochondrial haplotypes and found high sequence divergence (1.9%) between C. ferus and C. bactrianus. On the basis of a mitochondrial DNA sequence fixed difference, we developed a diagnostic PCR restriction fragment length polymorphism (PCR-RFLP) assay to differentiate between wild and domestic camel samples. We applied the assay to 81 individuals and confirmed the origin of all samples including five hybrids with known maternal ancestry. The PCR-RFLP system was effective for both traditional (blood, skin) and non-invasive samples (faeces, hair), as well as for museum specimens. Our results demonstrate high levels of mitochondrial differentiation between wild and domestic Bactrian camels and that maternal hybridization can be detected by a rapid and reliable PCR-RFLP system.


Assuntos
Camelus/genética , Mitocôndrias/genética , Animais , Feminino , Hibridização Genética , Masculino , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição
9.
Dent Assist (Waco Tx) ; 5(6): 16-7, 21, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3460719
10.
Dent Assist (Waco Tx) ; 5(6): 18-20, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3460720
11.
CDS Rev ; 76(2): 9-12, 1983 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6572110
12.
J Tenn Dent Assoc ; 62(2): 31-3, 1982 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-6961263
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...